Improved metal alloy for harness-trimmings



iitnittd $13125 patient ditto;

AUG. A. RANDALL, OF SOUTH BRAINTREE, ASSIGNOR TO HIMSELF. AND CHARLES F. WHITOOMB, OF BOSTON, MASSACHUSETTS.

Letters Patent N0. \l8,107, dated December 21 1869.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concern:

Be it lmown that I, AUG. A. RANDALL, of South Braintree, in the county of Norfolk, and State of Mars sachusetts, have invented an Improved Metal Alloy for Harness-Trimmings, &c.; and I do hereby declare i that the following is a description of my invention, snttioient to enable those skilled in the art to practise it.

My invention relates to the composition of a new alloy, to be used as a substitute for brass, iron, and other metals oralloys, in the manufacture of harnessrings and trimmings, metal ornaments, faucets, &c., my object being to. produce a metal which, having sufficient hardness, may be readily melted, and cast into shape in moulds, which will have asurface requiring only polishing to impart a finish thereto, which is easily polished,.and which has a bright, light steel or silvery surface, (upon being polished,) which surface will not easily tarnish,.an(l does not require coating', as the metal is of the same color throughout.

For this purpose, I usean alloy made up'of copper and tin, with arsenic added thereto, the proportions of the respective metals found best to answer, being one part of copper to five parts of tin, with about one per cent. of arsenic; and

My invention consists of an alloy, and articles made therefrom, composed of these metals so combined and treated.

In preparing the alloy, my method of procedure is as follows:

Taking, say forty pounds, of tin, and ten pounds of copper, l melt them together, and introduce into the crucible a cup filled with lumps of mineral arsenic, (about half a pound,) carrying the cup to the bottom of thevessel. As the arsenic becomes heated, the fumes thereof rise through and permeate the molten metal, and impart the requisite or desired degree of whiteness and hardness to the alloy, with a surface which retains its brightness when polished.

To this composition, when in a molten state, I deem it desirable to add about two ounces of cyanide of potassium, in powder, this causing the metals to combine freely, and holding them together under repeated meltings.

From experiment and observation, I find that this alloy can be melted and cast many times, without any marked alteration or separation of the metals. It gives ofi no arsenictl fumes, even when heated to near redness. It files well, and does not clog the file-teeth in the least. It takes a brilliant polish under thebnrnisher, and is brilliant, like silver, though not so white. It is not stained by sulphuretter-l'hydrogen, nor

even by sulphide ofammonium, both of which instantly I blacken silver and copper, and their alloys with each other. Its resistance to sulphur-compounds renders it superior to silver for many uses, and its burnished surfaceresists weak acids perfectly.

The alloy casts well, and gives a good copy of the pattern, since it expands on solidifying, and fills the mould.

Iron moulds, well smoked, are the best for castings,

and save the trouble of doing any turning or other finishing, except polishing orburnishing.

Though I have indicated the proportions of the respective metals now best known to me, it will be nnderstood that Ido not design to limit my in vention' to these exact parts, as, for particular uses, others may be better. Nor do limit myself to the manner of adding the arsenic, aslhe fumes may be otherwise combined with the molten metal.

, It will be obvious that the alloy can be practically used for the'production of most, if not all the small metals of hardware now made of brass or other metal compositions, as well as for many-articles now made of iron.

v I claim the metal alloy, substantially as set forth.

AUG. A. RANDALL. Witnesses R. l RANDALL, GEO. M. HOBBS. 

